Purpose
To compare results between standard and accelerated corneal collagen cross‐linking (CXL) for the treatment of progressive keratoconus.
Methods
We performed literature searches in PubMed, ...Cochrane Library, Web of Science, ISRCTN registry, ClinicalTrials.gov, and EMBASE for studies comparing conventional Dresden (C‐CXL) and accelerated CXL (A‐CXL). Outcomes were clinical results and changes in corneal properties. Weighted mean differences were used to evaluate the effects.
Results
Here, 22 studies with 1158 eyes (C‐CXL: 577 eyes; A‐CXL: 581 eyes) were included. At the last follow‐up, C‐CXL was superior regarding minimum keratometry (p < 0.00001) and demarcation line depth (p < 0.00001), whereas A‐CXL should be favoured when considering minimum corneal thickness (p = 0.0005). No differences in uncorrected and corrected distance visual acuity (p = 0.09 and 0.98), spherical equivalent (p = 0.11), spherical and cylindrical error (p = 0.29 and 0.32), maximal and average keratometry (p = 0.05 and 0.65), central corneal thickness (p = 0.15), corneal biomechanical properties (p ≥ 0.21 respectively), time of reepithelialization (p = 0.76), subbasal nerve density (p = 0.69), endothelial cell density (p = 0.30) and morphology (p ≥ 0.40 respectively) were found among both groups.
Conclusion
Consideration of less corneal thinning favours A‐CXL, whereas the deeper demarcation line and greater changes in minimum keratometric values in C‐CXL may indicate a higher treatment efficacy. Altogether, C‐CXL, as well as A‐CXL, provides successful results in the strengthening of corneal tissue.
Implantable collamer lens implantation (ICL) represents a safe and effective treatment for myopia and myopic astigmatism. To compare the outcomes of a bilateral one-stage same day approach to a ...two-stage approach, the databases of the University Eye Hospital Munich, Ludwig Maximilians-University and Smile Eyes Linz, Austria were screened for eyes that had undergone ICL implantation. Two-stage surgery was performed at an interval of 1 day (17 patients), 2 days (19 patients) and 1 week (2 patients). Variables analyzed were preoperative, 1-day and last follow-up uncorrected distance (UDVA) and corrected distance visual acuity (CDVA), manifest refraction, refractive spherical equivalent (SEQ), astigmatism, age, endothelial cell count (ECD), intraocular pressure (IOP) and ICL vaulting. In total, 178 eyes (100 eyes one-stage, 78 eyes two-stage) of 89 patients were included in this study. Mean follow-up was 1.1 ± 0.8 and 1.3 ± 0.5 years. Mean preoperative SEQ was - 7.9 ± 2.6 diopters (D) in the one-stage and - 8.0 ± 1.7 D in the two-stage group (p = 0.63) and improved to 0.00 ± 0.40 and - 0.20 ± 0.40 D at end of follow-up, showing slightly better stability in the one-stage group (p = 0.004). There was no difference in the efficacy (1.1 vs. 1.2, p = 0.06) and the safety index (1.2 vs. 1.2, p = 0.60) between the two groups. No eye (0%) in either group lost 2 lines or more of UDVA (p > 0.99). Refraction within ± 0.50 D and ± 1.00 D around target was achieved comparably often (89 vs. 86%, p = 0.65; 99 vs. 99%, p > 0.99). Endothelial cell loss was slightly higher in the two-stage group (1.3 vs. 4.3%). Vaulting at the final follow up was higher in the one-stage group (373.8 ± 205.4 µm vs. 260.3 ± 153.5 µm, p = 0.00007). There were no serious intraoperative complications in either group. In conclusion, this study demonstrates that both the one- and two-stage approaches are equally effective, predictable and safe. Regarding endothelial cell loss, vaulting and SEQ stability, the one-stage group showed slightly better outcomes, but these results are clinically questionable because they are so small. Larger studies are needed to quantitatively evaluate a potential benefit.
To evaluate the repeatability and validity of total corneal power measurements (total keratometry TK) obtained with a recently introduced optical biometer (IOLMaster 700, Carl Zeiss Meditec AG) to a ...Scheimpflug device (Pentacam, Oculus).
Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
Prospective randomized controlled trial.
The inclusion criteria were a corneal astigmatism of 3.00 diopters (D) or less, no previous ocular surgery, no known corneal irregularities, and no known dry eyes. All eyes were measured 3 times using the optical biometer and the Scheimpflug device. The results were statistically compared using Bland-Altman, within-subject SD, and astigmatism vector analysis.
Ninety-three eyes of 93 subjects were included. Overall, the repeatability of all eyes measured was 0.42 for standard K, 0.40 for TK, 0.45 for total corneal refractive power (TCRP), 0.43 for true net power (TNP), and 0.39 for simulated K. Bland-Altman analysis showed no significant difference between the optical biometer's TK compared with standard K and the Scheimpflug device's simulated K, TNP, and TCRP, the P value exceeding .05 in each case. A difference of >0.50 diopters between astigmatism measurements between TK and TCRP was found in 10 cases compared with standard K and TNP with 0 and 2 cases.
Repeatability of both devices was high, although measurements of meridian showed a great variability, suggesting that numerous measurements are needed to enhance accuracy. TCRP measurements between recently introduced TK and TCRP cannot be used interchangeably. Future studies are necessary to evaluate which measurement will result in a better outcome when respective measurements are used for toric intraocular lens calculations.
Purpose To compare immunocytochemical and ultrastructural characteristics of “lamellar hole–associated epiretinal proliferation” in lamellar macular holes with “conventional epiretinal membrane” in ...macular pseudoholes. Design A consecutive observational case series, laboratory investigation. Methods We analyzed surgically excised flat-mounted internal limiting membrane specimens and epiretinal membrane specimens removed from 25 eyes of 25 patients with lamellar macular holes (11 eyes) and macular pseudoholes (14 eyes) using interference and phase-contrast microscopy, immunocytochemistry, and transmission electron microscopy. By spectral-domain optical coherence tomography, epiretinal material of homogenous reflectivity without contractive properties was categorized as lamellar hole–associated epiretinal proliferation, whereas tractional epiretinal membranes presenting contractive properties were termed conventional epiretinal membrane. Results Lamellar hole–associated epiretinal proliferation was seen in 73% of eyes with lamellar macular hole. Eyes with macular pseudohole presented with conventional epiretinal membrane. In lamellar hole–associated epiretinal proliferation, positive immunoreactivity for anti–glial fibrillary acidic protein, hyalocyte markers, and anti–collagen type I and III was seen. In contrast, specimens of macular pseudoholes were positive for α-smooth muscle actin and anti–glial fibrillary acidic protein, predominantly. Cellular ultrastructure showed that lamellar hole–associated epiretinal proliferation of lamellar macular holes mainly consisted of fibroblasts and hyalocytes, whereas myofibroblasts dominated in conventional epiretinal membranes of macular pseudoholes. Conclusions Cells within lamellar hole–associated epiretinal proliferation appear to originate from vitreous and possess less contractive properties than cells of conventional epiretinal membranes. Our findings point to differences in pathogenesis in a subgroup of lamellar macular holes presenting lamellar hole–associated epiretinal proliferation on the retinal surface.
To compare the efficacy and safety of femtosecond laser-assisted cataract surgery (FLACS) with conventional cataract surgery (CCS).
Department of Ophthalmology, Goethe-University, Frankfurt am Main, ...Germany.
Meta-analysis.
PubMed, Cochrane Library, and EMBASE were systematically searched for studies comparing FLACS and CCS. Outcomes were efficacy and safety parameters. The effect measures were weighted mean differences or odds ratios with 95% CIs.
A total of 73 studies (25 randomized controlled, 48 observational) were reviewed with a total of 12 769 eyes treated with FLACS and 12 274 eyes treated with CCS. In eyes treated with FLACS, uncorrected and corrected distance visual acuities and spherical equivalent after 1 month to 3 months (P = .04, P = .005, and P = .007, respectively) were better, total and effective phacoemulsification times were shorter (P < .001 each), cumulative dissipated energy was less (P < .001), circularity was more accurate (P < .001), central corneal thickness after 1 day and 1 month to 3 months was less (P < .001 and P = .004, respectively), and endothelial cell loss after 3 to 6 weeks and 3 months was less (P = .002 and P < .001, respectively) compared with CCS. Anterior capsule ruptures occurred more often with FLACS. No significant differences among groups were found in visual acuity at 1 week and after 6 months or in posterior capsule rupture rates and endothelial cell loss after 6 months.
Both FLACS and CCS are effective and safe. FLACS required less ultrasound energy and a more precise treatment. However, mid-term visual acuity did not show any difference between both methods.
To compare the efficacy of a computer-assisted marker system for toric intraocular lenses (IOLs) (Callisto Eye System) with manual marking techniques.
University Eye Hospital Munich, ...Ludwig-Maximilians-University, Munich, Germany.
Prospective case series.
This study included patients having cataract surgery with implantation of a toric IOL (Torbi 709 M). They were randomly assigned to 1 of 2 groups based on the marking system used, manual or digital. Patients were included if they had age-related cataract and a regular corneal astigmatism of 1.25 diopters (D) or higher. Visual and refractive outcomes as well as rotational stability were evaluated. Vector analysis was performed to evaluate total astigmatic changes.
The study comprised 57 eyes of 29 patients; there were 28 eyes in the manual group and 29 eyes in the digital group. The mean toric IOL misalignment was significantly lower in the digital group than in the manual group (2.0 degrees ± 1.86 SD versus 3.4 ± 2.37 degrees; P = .026). The mean deviation from the target induced astigmatism was significantly lower in the digital group (0.10 ± 0.08 D versus 0.22 ± 0.14 D; P = .008). During surgery, the mean toric IOL alignment time was significantly shorter in the digital group (37.2 ± 11.9 seconds versus 59.4 ± 15.3 seconds; P = .003). The mean overall time required to perform the surgery was significantly shorter in the digital group (727.2 ± 198.4 seconds versus 1110.0 ± 382.2 seconds; P < .001).
A digital tracking approach for toric IOL alignment was efficient and safe to improve refractive outcomes. Furthermore, image-guided surgery helped streamline the workflow in refractive cataract surgery.
To compare the safety, efficacy, and patient-reported quality of vision of small incision lenticule extraction (SMILE) and implantable Collamer lens (ICL) implantation for the treatment of high ...myopia.
A database of 1,634 SMILE (Carl Zeiss Meditec AG, Jena, Germany) and 225 ICL implantation (STAAR Surgical, Monrovia, CA) procedures was screened for patients with a binocular preoperative manifest refraction spherical equivalent between -6.00 and -10.00 diopters (D) and plano target refraction. One-to-one matching was performed by preoperative manifest refraction spherical equivalent, age, and pupil size. All identified patients were then prospectively examined at their next regular postoperative follow-up visit and presented with the standardized and clinically validated Quality of Vision questionnaire to gauge patient-reported postoperative visual quality.
A total of 80 eyes (40 patients) were eligible for 1:1 matching. Mean postoperative follow-up was 27.8 ± 14.3 months in the SMILE group and 26.6 ± 17.7 months in the ICL group (P = .44). Regarding the percentage of eyes within ±0.50 D of plano target, refractive predictability was better in eyes treated with ICL implantation (90%) than SMILE (72.5%) (P = .045). Mean UDVA was comparable (ICL: -0.09 ± 0.10 logMAR; SMILE: -0.06 ± 0.09 logMAR; P < .09), but the efficacy (1.28 vs 1.05; P < .001) and safety (1.31 ± 0.22 vs 1.10 ± 0.25; P < .001) indices were higher after ICL implantation. ICL implantation induced significantly fewer higher order aberrations (total higher order aberrations: SMILE 0.724 ± 0.174 µm vs ICL 0.436 ± 0.114 µm; P < .01). Regarding subjective quality of vision, patients who had ICL implantation were significantly less bothered by visual disturbances, which were mainly halos after ICL and starbursts and fluctuations of vision after SMILE (P < .05).
In this refraction-matched comparative study, ICL implantation for high myopia yielded better refractive accuracy, better uncorrected distance visual acuity, fewer higher order aberrations, and better subjective quality of vision than SMILE. J Refract Surg. 2020;36(3):150-159..
Studying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related ...cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with "valleys and mountains " as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.
Myopia is the most common refractive error. Surgical correction with laser is possible. LASIK and SMILE are the techniques currently most used. Aim of the study was to compare changes in corneal ...volume and thickness after the respective laser treatment. 104 eyes of 52 patients were matched based on refractive error into two equally sized groups, either treated with LASIK or SMILE. Measurements were obtained from the Scheimpflug camera (Pentacam) preoperatively and at 3 and 12 months postoperatively. 3 months postoperatively, the flapless SMILE procedure resulted in a significant overall greater loss of corneal volume (P < 0.01) and corneal thickness (P < 0.01) compared to LASIK. No significant difference was found when comparing the 3 to 12-months values in each group. Within the currently used ranges of refractive error correction, loss in central corneal thickness and corneal volume with SMILE is higher in comparison to LASIK. As greater loss in corneal volume and thickness might contribute to higher level of corneal instability maximum ranges of refractive error correction with SMILE should not supersede those set currently for LASIK until more long-term results on corneal ectasia are available for SMILE.
To assess the clinical outcomes and patient satisfaction after bilateral cataract surgery with implantation of a bifocal refractive enhanced depth of focus intraocular lens (IOL) with a low near ...addition (add).
Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany.
Prospective longitudinal case series.
Eyes with bilateral age-related cataract and corneal astigmatism of less than 1.0 diopter (D) had standard microincision cataract surgery with implantation of a bifocal nondiffractive shape-segmented enhanced depth of focus IOL (Lentis Comfort, LS-313 MF15). The corrected and uncorrected (UDVA) distance visual acuities, uncorrected intermediate (UIVA) and near (UNVA) visual acuities, defocus, corneal astigmatism, spectacle independence, contrast sensitivity, rotational stability, photic phenomena, and patient satisfaction were evaluated over a 3-month follow-up.
The study comprised 22 patients (44 eyes). The mean postoperative manifest spherical equivalent was -0.10 D ± 0.58 (SD), resulting in a mean UDVA of 0.07 ± 0.10 logMAR, mean UIVA of 0.21 ± 0.15 logarithm of minimum angle of resolution (logMAR), and mean UNVA of 0.53 ± 0.15 logMAR. Binocular UDVA was 0.01 ± 0.08 logMAR. The best reading distance was 0.46 ± 0.09 m. More than 95% of patients were satisfied with their visual acuity, and less than 10% reported photic phenomena. The IOL showed an excellent rotational stability.
The enhanced depth of focus IOL with 1.5 D of near add showed excellent intermediate and far visual performance and acceptable near visual restoration. Patient satisfaction was very high, and few patients reported disturbing photic phenomena.
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